The Study And Implementation Of Blue Solid-state Laser By VCSEL Direct Frequency Doubling

Blue lasers have been widely used in many fields such as biological medicine, high density storage, laser projection and so on, which promote the research work of blue lasers to a high level. It is a relatively low-cost, high-reliability, small-volume, long-life and wide-use field lasers through directly secondary harmonic generation which is the most attractive and promising technique among other techniques that can produce blue lasers. Compared with edge-emitting diode lasers, vertical cavity surface emitting lasers have a lot of advantages such as narrow radiation angles, good quality optic spots etc. and gradually become the most suitable fundamental frequency lasers for the secondary harmonic generation. Composite resonator could make full use of the power of the fundamental frequency lasers to the maximum extent by coupling mode of the composite resonator. In our experiment both the direct double frequency technique and the composite resonator are employed and successfully obtained 490nm blue laser. Grin lens contributes a lot to adjust the shape of Gauss beam into good condition and shorten the longitudinal length of the resonator less than 20mm, and realize the goal of compact structure. With relative high secondary harmonic generation coefficient and wide acceptance angle, LBO crystal is chosen as the most suitable secondary harmonic generation crystal for blue lasers. In the experiment, when the output power of the fundamental frequency laser is 530mW, Gauss beam is adjusted by one grin lens whose length is 0.23p@980nm and focused on the end of LBO whose dimension is 2mm×2mm and length is 5mm, one blue beam of 50μW is obtained. And 70μW blue beam is obtained when an outer cavity mirror whose radius is 50mm is added.